This invention relates to cheese manufacture, particularly cheese of the pasta filata type.
Pasta filata cheeses are formed by submerging the curd in hot water and stretching to give a resultant filamentary configuration before further processing. They include pizza, mozzarella, scarmorze, becchi, provole, provolette, salame, provolone, mandarini and provolone giganti cheeses. The conventional process for making these cheeses is described in detail in Reinhold, Italian Cheese Varieties, Volume 1, Pfizer Cheese Monographs (1963).
Pasta filata cheese is produced initially in the same manner as conventional cheddar type cheeses. It can be manufactured from skim or whole milk, or a mixture of skim and whole milk. The milk may be raw, but is preferably pasteurized. When the milk is pasteurized, a starter organism such as mixed heat resistant lactobacilli can be added. After a ripening time of from 35 to 45 minutes, the milk may be set or coagulated by the addition of rennet diluted in water. The setting time is normally 30-35 minutes to form a smooth thick curd.
After the coagulum has reached the proper consistency resembling that of cheddar cheese, it is cut with curd knives, agitated and then cooked. The curd may then be drained with the curd particles agglomerating if left undisturbed. The curd may then be cut into blocks, which are then turned repeatedly. The blocks may be recut several times. During this operation (i.e. allowing the curd to agglomerate and then cutting and recutting) whey may be expelled from the curd and drained off through an outlet in the cheese vat.
When the above described operation is completed, and the curd reached a predetermined acidity, the cheese blocks may then be cut into small chunks or pieces in a cheese mill.
At this point cheddar cheese is produced by dry salting wherein the milled curd is mixed thoroughly with dry salt, placed into suitable drums, de-aerated to prevent mould growth and then cured such as by being maintained between 65.degree. and 80.degree. F. until a pH of around 5.0 is reached. The curing operation may take a very long time (e.g. from 5 weeks to 12 months).
In contrast to the production of cheddar cheese, cheese of the pasta filata type after milling is stretched in hot water, moulded to the desired shape and size, immersed in brine and then cooled. Alternatively the agglomerating, cutting and turning steps may be omitted and the curd soaked in hot water after cooking, the soaking being performed at an elevated temperature and lactose extracted therefrom before the curd is stretched, moulded, immersed in brine and cooled.
Therefore the principal difference between cheddar cheese and pasta filata cheese will be apparent, i.e. the latter is stretched or extruded to produce long filaments at one stage in its production which after the cooling step are ready for packaging and sale. On the other hand the cheddar cheese is always in block form and has to be aged for some considerable time before being ready for packaging.
Hitherto in the production of cheese of the pasta filata type, the usual method of salting by immersion in brine is unsatisfactory because the salt did not fully penetrate into the cheese, leaving an outer salted zone and an inner unsalted zone. This is not satisfactory because as salt is a preservative, the outer zone will be preserved at the expense of the inner zone, which tends to deteriorate and result in possible off-flavouring of the cheese. Therefore brined cheese was not always acceptable in quality. The process is also slow with the brining operation taking up to 72 hours in some cases. In addition the large brining vats require special housing space, and also the brining liquid is corrosive and its elimination would greatly reduce corrosion.
Attempts have been made to overcome this problem by direct salting of the milled pasta filata type cheese instead of brining. However this direct salting was found to be totally unsatisfactory because in the extended period of 15-30 hours of salting the cheese was rendered brittle and too acidic and could not be stretched in the subsequent extrusion step although direct salting has been satisfactory in production of cheddar cheese because it is always in the form of blocks or slabs and does not have a stretching step. Its use in production of pasta filata type cheese has not been practised on a large scale heretofore because of this reason.